Conventional thermoplastic extruders include machines that are fed with various types of granulated and solid thermoplastic materials.
These thermoplastic materials are heated and consequently melted. Then, they are pumped throughout the entire length of the pipe of said extruders, originating hollow, continuous and semi-solid filaments (molten material). The final shape and area sizes (height and width or diameter) of these filaments correspond to the shape and sizes of the extrusion head used in each extruder.
Conventional thermoplastic blowers comprise machines capable of expanding thermoplastic raw materials, providing them with a final shape pre-determined by the mold. Such raw materials are generally hollow and disposed within the water-cooled mold (said molds belong to the blowers in question), and then they are pressurized by compressed air flows. These flows cause the raw materials to expand equally and assume the shape identical to the shape of the mold cavities.
Bottles made of thermoplastic materials are generally produced by thermoplastic blowers.
The state of the art also comprises blower extruders, which are generally used in the manufacture of plastic bottles. A blower extruder, as its name suggests, combines a thermoplastic extruder with a thermoplastic blower, which will allow the extruded thermoplastic material to be directly blown.
A blower extruder, as described above, is in fact a blowing station coupled to an extrusion station. Conventionally, a blowing station includes components dimensioned to a single mold, that is, the current blowing stations belonging to the state of the art have only one outlet for molten thermoplastic material, and air outlets (perpendicular or transverse in relation to the inlet channel of thermoplastic molten materials) are consistent with the number of cavities existing in the molds. In short, each blowing station comprises only a single multiple cavity mold.
In addition to be an impeditive factor, it represents a major limitative factor, since it is necessary to install other blowing stations (if possible) when it is desirable to increase the production of a blower extruder. However, a blower extruder has a limited number of blowing stations (maximum two stations), and it occurs due to physical and mechanical factors.
Optionally, in order to achieve the desired increase in production, a second blower extruder is used. Such solution, which is financially expensive, demands physical space, and it is not always easily available in industries.
Therefore, from the aforementioned, it becomes obvious that is necessary to construct a blow-molding machine that solves the problems stated above, in an economic way, and without demanding excessive physical space.